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6500 power



  • Stefano - W2WTZ
    edited June 2017
    I made another check more accurate. Same conditions as previous test
    14,3V at power supply with voltage at radio 13,8V (by DDutil) under load
    no Atu, FM mode, pressing PTT. SSDR
    6500 HW
    Here the results:

    6m 95/91 W
    10m 99/97 W
    12m 95/94 W
    15m 95/93 W
    17m 91/89 W
    20m 91/87 W
    30m 91/89 W
    40m 87/85 W
    80m 89/87 W
    160m 87/85 W

    note. The first value is the power when pressing PTT, then holding it pressed, the
    second value is the power after 5 seconds, whe the reading is stable.
    The RF Power in SSDR shows some W more than real, maybe it's a normal tolerance.

    I find not practical to ask to the customer to provide 13,8V at the radio becouse most of fixed voltage power supply works at 13,8v. Anyway I made a quick test and the power increase 1W every 0,1V. This means that on 40 meters I should adjust the power supply at 15,8V to get 100W, Not acceptable in my opinion becouse in RX mode the radio receive a too high voltage.
    Tim, thank you for your reply, I will open the ticket as you suggest, but this means that Dan, Ross and many other should do the same. Flex invited many other customers with the same problem to open a ticket for further investigation. May I ask you if you solved the problem to them and how?

    If someone else can provide quite accurate power measurement is welcome to contribute.
  • k3Tim
    k3Tim Member ✭✭✭
    edited May 2020
    6500 : all measurements using software SDR meter readings
    into a 300 watt dummy load whilst in TUNE mode.

    6     104
    10   105
    12   100
    15     97    
    17     96
    20   100
    30     93
    40     92
    80     95
    160   93

    14.15 v_DC idle
    13.95 V_DC full load via s/w meter

    At first check the voltage was dropping to 13.5 - way to much. Reseating the power connector at the 6500 cured the large V-DC drop. Power supply is Astron linear 50Amp powering only the radio via a 10" pigtail of #10 wire. The above readings are FB by me. For more power, holding all other parameters constant one must increase the voltage while staying within spec. This assumes the Calibration settings are correct of course.

  • Stefano - W2WTZ
    edited June 2017
    Tim, Do you have the possibility to check the power uising an external wattmeter? It seems that the ssdr meter reading is about 5W too generous. Is possible to have a numeric (and not bargraph) reading of the output power?
  • Al_NN4ZZ
    Al_NN4ZZ Loganville GAMember ✭✭✭
    edited December 2016
    Hi Stefano,
    Re: is it possible to have a NUMERIC readout of the power.

    See this idea, it has been requested.....


    Regards, Al / NN4ZZ  
    al (at) nn4zz (dot) com
    6700 - HW.................. V
    SSDR / DAX / CAT...... V

  • luca Fossati
    luca Fossati Member
    edited April 2019
    There is my test on Flex 6300 on the same stefano's ericcson dummy load:

    6mtr - 102w
    10 mtr - 97w
    12mtr - 93w
    15mtr - 87w
    17mtr - 87w
    20mtr - 87w
    30mtr - 87w
    40mtr - 91w
    80mtr - 87w
    160mtr - 85w

    no ATU
    measured with external digital wattmeter connected with short rg213 pigtail

    software running smartsdr 1.8.3

    power supply 32Amp fixed 13.8v

    Voltage at the radio measured with software:
    13.85v in rx - dropping to 12.56v when in tx @ full power

    '73 de IZ2ZOZ
  • KY6LA_Howard
    KY6LA_Howard La Jolla, CA. Paris and Sablet FranceMember ✭✭✭
    edited July 2016

    Should be 13.8V at radio when in TX

    Either you need shorter power wires or larger wire size, or new Anderson Connectors or all of the above.

  • Stefano - W2WTZ
    edited July 2016
    Most of commercial power supply provvide 13,8v. The wire is supplied from Flex. When you buy a brand new Mercedes that is daclared for 100 mph it's hard to believe that to arrive at 100 mph you have to use a jet fuel and change the original tyres with the ones used by a truck.....
  • Stefano - W2WTZ
    edited July 2016
    Noce idea, I agree
  • Stefano - W2WTZ
    edited July 2016
    Nice sorry....t9 victim :)
  • Stefano - W2WTZ
    edited July 2016
    Howard, you are right if I wish to arrive at 110W, but the transceiver should provvide bolt on what is declared. Anyway even with higher voltate I don't arrive to the claimed power.
  • W9OY
    W9OY Alpha Team Member ✭✭
    edited July 2016
    Maybe you should go back and review Kirchhoff's loop law.  Wires count as resistors.  
    73  W9OY
  • G8ZPX
    G8ZPX Member
    edited July 2016
    ...and maybe you need to re-read his posts sir!

    He is already accounting for resistive drop in the cable (which should actually be minimal assuming the correct size was supplied by FRS).

    His PSU is at 14.3v to get 13.8v as measured internally by the radio (read via DDUTIL API).

    Isn't it reasonable to expect a radio to perform to the claimed spec when using the supplied cable, a 50A PSU, 14.3v input, the correct load/test procedure etc?

    If my radio was out by +/-2% against spec it would be taking a trip.

    Most of the recent Icom and Kenwood radios go well over the 100W output to make sure that the user will be able to realize 100W under typical user conditions.
  • Mack
    Mack Member ✭✭✭
    edited July 2016
    I use this one which ensures 13.8 at the Flex all the time. http://www.bkprecision.com/products/power-supplies/1901-1-32v-30a-switching-dc-power-supply.html Mack W4AX Alpha Team
  • HCampbell  WB4IVF
    HCampbell WB4IVF Member ✭✭
    edited June 2019

    From the ARRL Flex 6300/6700 test report, April 2015 QST:

     Measured in ARRL Lab:


    CW/SSB/FSK: HF, 1 W minimum, 84 – 99 W maximum depending on band.

    50 MHz, 1 – 86 W.

    * Power output typically 5 W lower at minimum operating voltage.


    CW/SSB/FSK: HF, 1 W minimum, 87 –99 W maximum depending on band.

    50 MHz, 1 – 82 W.

    * Power output typically 5 W lower at minimum operating voltage.

  • EA4GLI
    EA4GLI Salvador Member ✭✭✭
    edited July 2018
    I think FRS lost a great opportunity to make this a 150w or even 200w rig.... but consistently being below 100w for a vast majority of users is unfortunate.

    I understand that the practical difference is small (I wouldn't call almost 20% dismissable) but why not give me 105 to 120w instead of 80 to 95w. 

    The 6700 tops the Sherwood list by a smaller percentage... but it is on the top with 108dB. 15 to 20% less than that puts it in the company of a very large group of superhet radios.

    I hope that this can be fixed with software.... but it just doesn't seem the case, otherwise... why don't we have a fix it already?

    I use an amplifier that needs very little drive so I don't fret over the power, but with every revision of the software I test the power and it is always low... and it is disappointing.
  • KC2QMA_John
    KC2QMA_John Member ✭✭
    edited December 2016
    My TEN TEC Orion II with the same supply, cable length and gauge as my flex 6500 and I get 125w on most bands.
  • Stefano - W2WTZ
    edited February 2018
    Steve already explained in much better english than mine that I COMPENSATED THE VOLTAGE DROP. I really don't know how to explain you in other words that from power supply exits 14,3V and inside the radio, under load, arrives 13,8V. If Elmer you don't undestand this, is becouse you do not want to understand it, sorry, I give up.
    I can use a remote sensing or a thermonuclear gauge made by aliens to read an accuracy of 0,000000001V, but in 40 meters I have 85W and it's evident that it's not a matter of voltage. Results of ARRL Lab are not enough clear? They tested hundred of radios, only with flex they have to change measure system and procedures?
    Flex in the site and catalogues advertise a 100W radio at 13,8V. I bought what advertised.
    I suspect that what declared is not true, infact I asked to know how they fixed this problem to other Hams that opened a ticket and there is no reply, that is itself a reply...
    You are right Salvador, If I had a PA whose input requires 100W with 6500 you can't arrive to it's max output. I use 6500 on QRP or with Acom solid state PA at 13W so I don't care of 85W, but I bought a 100W Transceiver and I wish from Flex Lab a clear and true official communication. They had 2 years for "further investigations", more than enough.
    It's a 85W tranceiver? No problem Flex, tell us, 6500 remains a wonderful materpiece and I am very very glad of it.
  • EA4GLI
    EA4GLI Salvador Member ✭✭✭
    edited November 2016
    You can test something... When the radio is on you can tap 3 times on the left arrow, then 1 time on the right arrow and then tap once in the OK key.
    That brings to the LCD screen a readout with voltages.


    Even though DDUtil reads 13.9v for my radio, this presents 13.61v and 13.39v.
    If I TUNE with 100W the number goes down to 12.7v - 12.3 respectively.
    Maybe you can test with your power supply and find out what are the readings on your 6500. I still hope that this is a software-firmware "issue".

    I tried in the past with an adjustable power supply that brought the voltage up to 15v. Still no significant difference in output. So I went back to my fix 13.9v output PSU (it is a quieter power supply).

    Once you are done with the readout on the 6500 you can push OK again to stop the refresh of the voltages and then select the Radio ID from the Radio Setup Menu to clear the numbers on the screen.


    Let's hope FRS understand our reasoning behind the disappointment from the low power numbers and can find a solution.

  • DON
    DON Member ✭✭
    edited July 2016
    100 watts vs. 85 watts....
    10 log(100 / 85) = 0.70dB
    1 s unit = 6dB
    I don't think there is any way the guy on the other end will notice the difference.
  • EA4GLI
    EA4GLI Salvador Member ✭✭✭
    edited November 2016
    DON, while I completely agree with your numbers I pointed out on my previous post how the 6700 was on the top of Sherwood list by a very small margin... outside of a lab probably the differences between the top 10 transceivers are not really perceptible... but that small difference makes it the top radio. 

    As Stefano pointed out... it is not about the difference between 85w and 100w as much as expecting 100w and getting 85w. If the difference was the other way around, expecting 100w and getting 110w no one would complain.
  • Bill -VA3WTB
    Bill -VA3WTB Member ✭✭✭
    edited December 2016
    Best thing Is call Flex and complain then. We know the radio can do 100W, it does on some bands.
  • K4MT
    K4MT Member
    edited July 2016
    I agree. If i pay for a bottle of **** I expect it to be full.
  • ole puschl
    ole puschl Member
    edited July 2016
    Here are my measurements.

    Flex 6500, 300 watt dummyload, Array solutions Powermaster II powermeter
    Dutill: volt at idle: 14.0  Dutill volt with flexradio at 100 watt output: 13.2 v

    on 80 meter: SSB tune:
    tune power slider: 100 watt
    flex internal powermeter  94 watt
    flex internal SWR meter: 1.0
    Array solution powermeter: 98 watt
    Array solution powermeter: SVR: 1.00

    on 20 meter: SSB tune:
    tune power slider: 100 watt
    flex internal powermeter  98 watt
    flex internal SWR meter: 1.0
    Array solution powermeter: 101 watt
    Array solution powermeter: SVR: 1.00

    seems ok to me

    OZ1OP / Ole
  • W9OY
    W9OY Alpha Team Member ✭✭
    edited October 2019
    I copied this list from Stephano's double list (above) and made calculations for the first number in that series.  The right list is how many dB below 100W the measured value is.  

    6m 95 W           -0.2 dB
    10m 99 W         -0.04 dB
    12m 95 W         -0.2 dB
    15m 95 W         -0.2 dB
    17m 91 W         -0.4 dB
    20m 91 W         -0.4 dB
    30m 91 W         -0.4 dB
    40m 87 W         -0.6 dB
    80m 89 W         -0.5 dB
    160m 87 W       -0.6 dB

    What this means is on 80M, at 89W my signal is 0.5 dB weaker than if my signal was 100W, a virtually immeasurable amount at the receiving end.

    I think the idea that Flex is supposed to spec the input voltage of the radio anywhere else but at the terminals or somehow needs to guess what power supply will be used is nonsense and all the hand waving to support this argument is BS.  I run my radio with 14.5V under no load measured at my power supply with a Fluke.  It took exactly 10 min to pop the top of my PS and adjust Vr   This also reports 14.5v on DDUTIL under receiver load.  Under transmit into a dummy load my voltage drops to 13.9v as measured on DDUTIL.  I get outputs very similar to Stephano and these are quite satisfactory.  My radio is perfectly stable, and the temp is quite acceptable even under extended operation.  

    The problem with getting every last **** watt is the power devices are more thermally stressed.  I have a friend with a TS2000 who blows up his radio about every 6 months and then **** to high heaven, because he has to get every last **** watt.  I'd rather be 0.5 dB weaker.

    73  W9OY 
  • Stefano - W2WTZ
    edited July 2016
    Always something to learn here...thank you Salvador for yr suggestion, I will try, but I think that the 15 missing W cannot be caused by few millivolt and anyway I don't agree that is normal for a top end radio to have all this hassle to work on millivolts with adjustable power supply to arrive close as possible to 100W declared...
    Don I agree, but did you try to drive at 100 or 85 W a 4 kw PA? As written, I don't care, but the technical specifications must be true.
  • Tim - W4TME
    Tim - W4TME Administrator, FlexRadio Employee admin
    edited December 2016
    If you suspect you have a hardware related issue, please open a HelpDesk support ticket.
  • KC2QMA_John
    KC2QMA_John Member ✭✭
    edited December 2016
    Question: Does FRS approve running the radio at 14.5?
  • K4MT
    K4MT Member
    edited July 2016
    Why does my Kenwood and Icom give full power with PS set to 13.8 at the supply?  Many people do not have adjustable power supplies and if they do they do not want to put higher voltage into their other rigs when 13.8 at the supply has been the spec for most radios.  

    I agree the lower output is not going to be heard at the other end.  I do not believe that is the point the OP made.  I believe he like others feel a 100 watt radio should put out close to 100W with normal power supply settings. 15 watts low is not what I see with other radios I have owned. A valid point in my opinion.
  • KC2QMA_John
    KC2QMA_John Member ✭✭
    edited December 2016

    Yes this is about RF power output NOT about what the signal level is to another receiving station.

    So does FRS approve running the radio at 14.5v? Somehow I doubt it.
  • spopiela
    spopiela Member ✭✭
    edited December 2016
    If my calculations are correct, 100w will only extend your range by about 8 percent over a value of 85 watts. This assumes direct transmission and reception between two points with no other reception factors included. I agree that a spec is something that you are buying and should be defined appropriately and tested accordingly.

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